Dr. Jennifer Pett-Ridge (Environmental Isotope Systems Group, Lawrence Livermore National Laboratory (LLNL), USA)
Since the dawn of agriculture, cultivated soils have lost a vast amount of carbon to the atmosphere. Investing in management practices that “repay our carbon debt” and rebuild soil carbon reserves in agricultural landscapes is a key negative emissions strategy with possible co-benefits for sustainable food, fiber and biofuel production. To understand and promote the effects of soil microorganisms that lead to stable soil carbon, it is critical to understand how microbial ecophysiological traits are linked to soil organic matter formation, and how cross-kingdom interactions—involving bacteria, fungi, archaea, protists, microfauna and viruses—shape soil carbon availability and loss. I will present results from studies where we have used quantitative stable isotope probing (SIP) and metagenomics/transcriptomics to assess growth and mortality of wild microbial and viral communities and show how niche differentiation in space and time drives the soil carbon cycle.